The present invention generally relates to fuel-fired heating appliances and, in a preferred embodiment thereof, more particularly provides a specially designed inner door/burner assembly for a gas-fired water heater.
As conventionally constructed, a gas-fired water heater has a combustion chamber opening outwardly through a side wall access opening and having disposed therein main and pilot burner assemblies respectively supplied with gas via main and pilot gas supply tubes connected to the burner assemblies and extending outwardly through the side wall access opening. When the water heater is initially fabricated, the in-place main and pilot gas burners in the combustion chamber are lit and tested by passing a lighting wand inwardly through the side wall access opening into the combustion chamber and lighting the burners. If the burner test is successful, an inner access door is then placed over the side wall access opening, with slots in the door receiving the previously installed gas supply tubes extending into the combustion chamber through the side wall access opening.
This well known conventional assembly and testing method has several limitations and disadvantages. For example, because the inner access door is separate from the main and pilot gas supply tubes, it is difficult to form an adequate seal between the inner access door being installed and the previously installed main and pilot gas supply tubes. Additionally, several separate steps are required in installing the door, the burners and the gas supply tubes, thereby undesirably adding to the complexity and overall cost of fabricating the water heater.
In view of the foregoing it can readily be seen that a need exists for an improved inner door construction for a fuel-fired water heater that eliminates or at least substantially reduces the above-mentioned limitations and disadvantages associated with conventional inner door constructions and associated door installation techniques. It is to this need that the present invention is primarily directed.
In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a specially designed access door/burner assembly is provided for use with a fuel-fired heating appliance, representatively a gas-fired water heater, having a combustion chamber opening outwardly through a side wall access opening in the appliance.
The access door/burner assembly comprises an access door member securable to the heating appliance over the side wall access opening, the door member having a burner test lighting opening therein. A sight glass structure is snap-fittable into the burner test lighting opening, and a fuel supply tube structure, including main and pilot fuel supply tubes, is anchored to and sealingly extends through the access door member. A burner structure is operatively secured to the fuel supply tube structure and is movable into and out of the combustion chamber in respective response to placement of the access door member on the side wall of the heating appliance and removal of the access door member from the side wall portion of the heating appliance. Representatively, the burner test lighting opening in the access door member has a peripheral notch therein, and the sight glass structure has a resilient tab portion snap-fitted into the notch.
The unique configuration of the access door/burner assembly facilitates the installation thereof on the heating appliance, and also facilitates the initial lighting and testing of the appliance""s burner structure. In carrying out a method of the present invention, the access door member, with its burner lighting and testing opening uncovered, is moved toward the appliance""s access opening, to operatively place the burner structure within the combustion chamber, and then suitable secured to the appliance side wall portion. A lighting structure, such as a conventional lighting wand, is then inserted through the access wall opening and used to light and test the burner structure within the combustion chamber. After the burner lighting and testing procedure is completed, and the lighting structure withdrawn from the combustion chamber, the sight glass structure is snapped into place within the previously open burner lighting and testing opening in the installed access door member.
The special configuration of the access door/burner assembly substantially simplifies the installation of both the burner structure and the access door portions of the heating appliance, and at the same time provides for a simple and easy lighting and testing of the burner structure within the combustion chamber.
According to another feature of the present invention, a passthrough tube is extended through and anchored to the access door member, and a plurality of wires, illustratively thermocouple and igniter wires, are sealingly extended through the pass-through tube utilizing a specially designed resilient plug member.
In a preferred embodiment thereof, the resilient plug member has a tapered cylindrical configuration and is radially split into first and second halves which are foldable about a peripheral flap portion of the plug member between an open position in which flat sides of the plug halves extend in opposite directions from the peripheral flap portion, and a closed position in which the flat sides face and abut one another. The flat sides of the plug halves have recesses therein which are configured to receive side portions of the thermocouple and igniter wires. Alternatively, the plug may be configured to (1) sealingly receive the pilot fuel supply tubexe2x80x94either by itself or in addition to either or both of the thermocouple and igniter wires, or (2) sealingly receive either of the thermocouple and igniter wires by itself.
The wires are sealingly extended through the pass-through tube by placing side portions of the wires in associated ones of the side recesses with the sealing plug member in its open position and then folding the plug member to its closed position. The closed sealing plug member is then coaxially placed and radially wedged into the pass-through tube. One or more of the wires may be fixedly secured to the sealing plug member if desired.
While principles of the present invention are representatively incorporated in a gas-fired water heater, it will be readily appreciated by one of skill in this particular art that such principles may alternatively be utilized to advantage in a variety of other types of fuel-fired heating appliances such as, for example, fuel-fired boilers and air heating furnaces.